Method of creating production plan of demand variation input type and method of creating production plan minimizing risk of demand variations

Abstract

A production plan is created so as to minimize risk of demand variations. Forecasted values of amounts of requests are entered for each different item of products, markets, dates, past accuracy of demand forecasts, and order achievements at the time when the plan is created. Scenario information is created in which assumable amounts of request for each different item of the products, markets, and dates and probabilities at which the amounts of requests agree with actual amounts of requests are defined. Management indexes are found from the amount of stockout and amount of stock calculated in each different scenario, based on the scenario information, target values of the management indexes, and information on strongpoints. An amount of production that maximizes the achievement ratios of the management ratios to their targets within the ranges of supplied materials and within the range of the production capacity is calculated by an optimization algorithm.

Description

BACKGROUND OF THE INVENTION [0001] The present invention relates in general to the forecasting of a number of products required by the market before a demand for such products is established, the ordering of materials for the products, and the manufacture of the products; and, more particularly, the invention relates to a technique associated with a method of creating a production plan that minimizes the managerial risk caused by out-of-stock and overstock conditions created by errors in forecasting the demand for a product at the time when the materials are ordered. [0002] In a manufacturing industry where speculative productions are performed, the number of ordered products is forecasted before an order for the product is established. Then, the materials are ordered. Generally, a long time of more than one month is required to procure the materials. Therefore, the amount forecasted at the time when the materials are ordered may be different from the actual demand. Where the actual...

AI Technical Summary

Benefits of technology

[0007] In view of the foregoing problems, the present invention has been made. It is an object of the present invention to provide a method of creating a production plan that is capable of preventing overstock and out-of-stock conditions as much as possible without adjusting the oversupply or undersupply of materials or the production capacity, even if demand variations take place. It is another object of the present invention to provide a technique for automatically determining a method of creating a production plan appropriately according to the process of the product life cycle.

[0009] Furthermore, in accordance with the present invention, management indexes capable of quantitatively evaluating a production plan, such as a stockout rate and a stock turnover rate, are adopted as indexes for quantitatively evaluating the risk of demand variations. Target values of the management indexes are previously set. An amount of production that maximizes the achievement ratios of the management indexes to their targets within the ranges of amounts of supply of materials and the range of the production capacity is regarded as a production plan that minimizes the risk of demand variations.

Problems solved by technology

Generally, a long time of more than one month is required to procure the materials.

Such conditions may lead to a loss in profit.

Furthermore, the out-of-stock condition will incur a decrease in the amount of sales, putting pressure on the corporate management.

Especially, where the amount forecasted at the time when the materials are ordered is greatly different from the actual demand, the amount of adjustment is large.

Furthermore, in some cases, it is impossible to fully compensate for an oversupply or an undersupply of materials or to adjust the load on the production line in spite of the fact that the introduction plan has been created with many process steps.

In particular, when materials are ordered, it is assumed that a certain amount of shortage will occur.

However, with the techniques disclosed in the above-cited JP-A-11-96210 and JP-A-9-277142, it is only possible to adjust one of oversupply or undersupply of materials or an excess of production capacity produced by demand variations.

It has been impossible to adjust both at the same time.

Therefore, when the transition of a variation of a forthcoming amount of a request is greatly different from the transition of a variation of the past sales achievements, as typically occurs in the initial or last stage of a product life cycle, an appropriate safe stock quantity cannot be set.

This results in an overstock or out-of-stock condition.

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